04 Immunology Flashcards
illustration of antigen processing and presentation?
https://www.dropbox.com/s/6g3zee05j7k3r17/Screenshot%202013-11-07%2000.29.54.jpg
what is the most abundant antibody in the body?
IgG
which antibody is for allergic reactions, parasite infections?
IgE
what are examples of type II hypersensitivity reaction?
ABO blood incompatibility, graves’ disease, myasthenia gravis
what do cytotoxic T cells do?
recognize and attack non-self antigens attached to MHC class I receptors (eg viral gene products)
what is type II hypersensitivity reaction mediated by?
IgG or IgM reacts with cell-bound antigen
what is the structure of MHC class I?
single chain w 5 domains
what do cd4 cells release?
release IL2, IL4
what antibody is responsible for secondary immune response?
IgG
what happens through the immunologic cascade when bacterial infections occur?
endocytosis by APCs (antigen presenting cells), proteins get bound to class II MHC molecules, go to cell surface, are recognized by CD4 helper T cells –> B cells which have already bound to the atigen are then activated by the CD4 helper T cells; they then produce the antibody to that antigen and are transformed to plasma cells and memory B cells.
where are MHC class I cells located?
all nucleated cells
what does IL2 do?
causes maturation of cytotoxic T cells
what is type IV hypersensitivity reaction mediated by?
antigen stimulation of previously sensitized T cells.
what is type I hypersensitivity mediated by?
eosinophils have IgE receptors for antigen and they release major basic protein
what does MBP activate and eventually cause release of what?
activates mast cells and basophils, and releases histamine, serotonin, bradykinin
what are the types of antibodies?
IgG, IgM, IgA, IgD, IgE
what is the initial antibody made after exposure to antigen?
IgM
what is the cell cascade when a pt gets a viral infection?
endogenous viral proteins produced, are bound to class I MHC, go to cell surface, recognized by CD8 cytotoxic T cells
what are the types of MHC classes?
MHC class I (A,B, and C) and class II (DR, DP, DQ)
what are examples of type I hypersensitivity reaction?
bee stings, peanuts, hay fever
what do suppressor T cells do?
regulate CD4 and CD8 cells
where are MHC class II cells located?
antigen-presenting cells (monocytes, dendrites)
how do you test cell-mediated immunity?
intradermal skin test (ie TB skin test)
what type of infections are associated with defects in cell-mediated immunity?
intracellular pathogens (TB, viruses)
which antibodies fix complement?
IgM and IgG. They require 2 IgGs or 1 IgM
what does IL4 do?
causes B-cell maturation into plasma cells
what kind of hypersensitivity is CD4 involved in?
delayed-typed hypersensitivity
what do plasma cells do?
secrete antibodies
describe T and B cell activation through illustration.
https://www.dropbox.com/s/sogscx8m9wrjqnt/Screenshot%202013-11-07%2000.34.36.jpg
what is MHC class I function?
target for cytotoxic T cells (CD8). they bind T-cell receptor
what are the types of hypersensitivity reactions?
I: immediate hypersensitivity reaction (allergic)
II: antibody mediated hypersensitivity reaction
III: immune complex deposition hypersensitivity reaction
IV: delayed-type hypersensitivity reaction
what is special about NK cells?
not restricted by MHC, do not require previous exposure, do not require antigen presentation. Not considered T or B cells
what is the name of CD4 cells?
helper T cells
what do MHC class II do?
activate helper T (CD4) cells by binding T cell receptor and stimulates antibody formation after interaction w B cell surface IgM
why are T cells called T cells and B cells called B?
Thymus and Bone
what type of cells are part of the body’s natural immunosurveillance for cancer?
NK cells
what is the structure of MHC class II?
2 chains w 4 domains each
what are the types of CD8 cells?
suppressor T cels and cytotoxic T cells
what cells do natural killer cells recognize?
cells that LACK self-MHC
which antibody is a membrane-bound receptor on B cells, serving as an antigen receptor?
IgD
what are examples of type III hypersensitivity reaction?
serum sickness, SLE
what makes B cells become plasma cells?
IL4 from T cells
what is type III hypersensitivity reaction mediated by?
immune complex deposition
which antibody gives newborn protection by crossing through placenta?
IgG
what antibody is found in secretions? where else is it found?
IgA. found in peyer’s patches in gut, breast milk (for newborns), prevents microbial adherence and invasion in gut.
what is delayed type hypersensitivity?
brings in inflammatory cells by chemokine secretion
what part of the antibody is recognized by PMNs and macrophages?
constant region
which antibodies are opsonins?
IgM and IgG
what is the difference between polyclonal and monoclonal antibodies?
polyclonal has multiple binding sites to the antigen at multiple epitopes. monoclonal has only 1 binding site to 1 epitope
what is the largest antibody?
IgM. Has 5 domains (10 binding sites)
what part of the antibody does antigen recognition?
variable region
when do you give tetanus immune globulin?
give only with tetanus-prone wounds in pts who have not been immunized or if immunization status is unknown
what cell is the major source of histamine in the tissue?
mast cell
what is an immunologic chimera?
2 different cell lines in one individual (eg bone marrow transplant pts)
what are examples of delayed-typed hypersensitivity reaction?
TB skin test (PPD), contact dermatitis
what are the secondary lymphoid organs?
spleen and lymph nodes
what are tetanus prone wounds?
(> 6 hrs old, obvious contamination and devitalized tissue; crush, burn, frostbite, or missile injuries
what cytokine has shown success for melanoma?
IL-2
what are the primary lymphoid organs?
liver, bone, thymus
what cell is the major source of histamine in the blood?
basophils
what does IL2 do to tumors?
converts lymphocytes to lymphokine-activated killer (LAK) cells by enhancing their immune response to tumor
what cytokine converts lymphocytes to tumor infiltrating lymphocytes?
IL-2
when do you give tetanus toxoid?
in non tetanus prone wounds: only if pt has received < 3 doses or tetanus status is unknown
in tetanus prone wounds: always give tetanus toxoid unless >= 3 doses and it has been < 5 years since last booster
